Re: New standby_slot_names GUC in PG 17

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, Tom Lane <tgl@sss.pgh.pa.us>, Muhammad Ikram <mmikram@gmail.com>, Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Nathan Bossart <nathandbossart@gmail.com>
Date: 2024-06-25T04:54:41Z
Lists: pgsql-hackers
On Tue, Jun 25, 2024 at 8:20 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> On Tue, Jun 25, 2024 at 11:21 AM Zhijie Hou (Fujitsu)
> <houzj.fnst@fujitsu.com> wrote:
> >
> > I agree the current name seems too generic and the suggested ' synchronized_standby_slots '
> > is better than the current one.
> >
> > Some other ideas could be:
> >
> > synchronize_slots_on_standbys: it indicates that the standbys that enabled
> > slot sync should be listed in this GUC.
> >
> > logical_replication_wait_slots: it means the logical replication(logical
> > Walsender process) will wait for these slots to advance the confirm flush
> > lsn before proceeding.
>
> I feel that the name that has some connection to "logical replication"
> also sounds good. Let me add some ideas:
>
> - logical_replication_synchronous_standby_slots (might be too long)
> - logical_replication_synchronous_slots
>

I see your point about keeping logical_replication in the name but
that could also lead one to think that this list can contain logical
slots. OTOH, there is some value in keeping '_standby_' in the name as
that is more closely associated with physical standby's and this list
contains physical slots corresponding to physical standby's. So, my
preference is in order as follows: synchronized_standby_slots,
wait_for_standby_slots, logical_replication_wait_slots,
logical_replication_synchronous_slots, and
logical_replication_synchronous_standby_slots.

-- 
With Regards,
Amit Kapila.



Commits

  1. Update release notes to reflect recent commit 0f934b0739.

  2. Rename standby_slot_names to synchronized_standby_slots.

  3. Add a new slot sync worker to synchronize logical slots.